What are Insulating Concrete Forms?

Insulating concrete forms are a stay-in-place concrete form that
consists of two expanded polystyrene panels (EPS) usually sized 16"
in height, 48" long and approximately 2 1/2" in thickness, spaced
apart the desired wall thickness. Polypropylene webs (or
ties) are spaced 6" or 8" on centre to withstand the concrete pressure and to
allow the attachment of wall finishes (damp proof membrane or rainscreen on the outside,
drywall on the inside).

Concrete is placed into the cavity between the two panels, with
the panels and ties staying permanently with the concrete wall,
hence the name "stay in place" concrete form. The EPS panels provide
a minimum insulation value of about R24. Increased panel thicknesses
can achieve R30 and R40.

ICFs Up to 60% Higher Thermal Efficiency than 2x6 Wall

The attached report prepared by CLEB Laboritories Inc. comparing the thermal performance of an 8" ICF wall compared with
an insulated wood frame wall in accordance with test procedure ASTM C1363-11. The report shows that the ICF wall can achieve up
to 60% energy savings with a R-Value 58% higher than the stud wall.

Click up image to the right to see the full report.

Below Grade ICF Walls

Below grade foundation walls are typically formed with 3/4" plywood + metal ties to withstand the concrete
pressure. Once the concrete has hardened, the plywood is stripped by breaking each tie on both sides of the concrete and removing the
plywood.

Concrete damage to the plywood ultimately leads to the forms being scrapped. The cost of transport, cleaning and storage
determine the cost of plywood rentals.

To provide thermal performance and allow attachment of wall finishes, a 2x4 or 2x6 stud wall is built on the inside and fiberglass
batts installed between the studs.

With the building code requiring increased levels of thermal performance, ICFs are now a viable economic alternative. ICFs not
only form the concrete, but stay in place to provide thermal performance and attachment points for drywall on the inside and damp
proof membrane on the outside.

Plywood formed basement walls are notorious for allowing ground moisture to wick in through the concrete (rising
damp), leading to the damp musty smell in most basements. ICFs
eliminate this problem as long as the footing is protected with a
suitable membrane (Fastfoot®).

Cost Analysis for Below Grade Foundations

When the ICF wall is monopoured with the footing (ICF + MP + Helix®
method), the ICF MP option is more cost effective that the
traditional plywood + stud wall alternative. Click
this link to view the below grade cost analysis.

Above Grade ICF Walls

Above grade walls have typically been been constructed with 2x4
or 2x6
studs, plywood (or OSB) sheathing, with fiberglass batts between the
studs. With higher levels of thermal performance now been demanded,
new wall assemblies are being developed to reduce the thermal
transfer through the wood studs, such as the installation of
insulation on the outside of the sheathing to reduce thermal bridging.

ICFs are worthy of consideration for above grade walls for the
following reasons: